Patents by Inventor Yukio Atsumi

Yukio Atsumi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Mobile communication system, mobile terminal, and mobile communication method
    Patent number: 7400601
    Abstract: It is an object of the present invention to provide a mobile communication system capable of shortening a delay time preceding the reception of a multicast packet at a radio base station which has been reached by a movement of a mobile terminal. The mobile communication system includes a multicast router, a data layer link switch, a radio base station, and a mobile terminal. In cases where the mobile terminal detects switching of the radio base station but does not detect switching of the multicast router, a path establishing request, a withdrawal request, and another path establishing request are sequentially output. When the switching of the radio base station and the switching of the multicast router is detected, a path establishing request is transmitted to the new multicast router, and a withdrawal request is transmitted to the previous multicast router thereafter.
    Type: Grant
    Filed: March 26, 2004
    Date of Patent: July 15, 2008
    Assignee: NTT DoCoMo, Inc.
    Inventors: Yuki Moritani, Yukio Atsumi
  • Mobile communication system, mobile terminal, and mobile communication method
    Publication number: 20040213177
    Abstract: It is an object of the present invention to provide a mobile communication system capable of shortening a delay time preceding the reception of a multicast packet at a radio base station which has been reached by a movement of a mobile terminal. The mobile communication system includes a multicast router, a data layer link switch, a radio base station, and a mobile terminal. In cases where the mobile terminal detects switching of the radio base station but does not detect switching of the multicast router, a path establishing request, a withdrawal request, and another path establishing request are sequentially output. When the switching of the radio base station and the switching of the multicast router is detected, a path establishing request is transmitted to the new multicast router, and a withdrawal request is transmitted to the previous multicast router thereafter.
    Type: Application
    Filed: March 26, 2004
    Publication date: October 28, 2004
    Inventors: Yuki Moritani, Yukio Atsumi